DATABASE SYSTEM MULTIPLE CHOICE

Database (DB)

A collection of data that is stored and organized in a way that makes it easy to access, update, and manage.

Database Management System (DBMS)

A collection of interrelated, structured, and organized data along with a set of programs that access and manage that data. It serves as an interface between the database, the user, and applications, providing controlled access, data manipulation, and integrity maintenance.

Metadata

Data about data.

Data Dictionary

A component of a DBMS where metadata is stored.

Tablespace

A logical unit of storage that consists of at least one datafile where database schema objects (like tables and indexes) are stored.

Distributed Database (DDB)

A database in which data is spread over several computers that are interconnected by a communications network.

Distributed Database Management System (DDBMS)

Software that manages the distributed database and provides an access mechanism that makes this distribution transparent to users.

MySQL

A popular, dual-licensed (GPL and commercial) relational database management system originally developed in the mid-1990s.

DBeaver

A desktop SQL client and database management tool written in Java that interacts with databases through a JDBC driver.

Conceptual Design

The design phase that describes the information to be contained in the database and the relationships between the data, typically represented by an ER model.

Logical Design

The phase that defines the structure of the database (or DB schema), including tables, attributes, and relationships.

Entity

A real-world object (or abstract concept) about which we want to store information.

Attributes

The data that define an object or entity.

Relationship

An association between entities that reflects interactions between them.

Cardinality

Defines how many instances of one entity can be related to a single instance of another entity through a relationship. It is written using (min, max) pairs.

Min Value

The minimum number of times an entity must participate in a relationship.

Max Value

The maximum number of times an entity can participate in a relationship.

Key

A set of attributes sufficient to distinguish the occurrences of an entity from each other.

Super Key

A set of one or more attributes which, taken collectively, allow an entity to be uniquely identified.

Primary Key

A candidate key chosen by the database designer to identify entities within a set, which cannot have repeated or NULL values.

Foreign Key (External Key)

An attribute that is a primary key in another table, included in a different table to enable a relationship between the two.

Normalisation

The process of verifying and ensuring the consistency of data and the efficiency of its manipulation, designed to avoid data redundancy, update anomalies, and deletion anomalies.

SQL

A domain-specific programming language designed to manage, manipulate, and retrieve information from relational database management systems.

DDL (Data Definition Language)

Allows programmers to define the structures that will store the data (e.g., using CREATE, ALTER, and DROP commands).

DML (Data Manipulation Language)

Allows users to query or modify data (e.g., using SELECT, INSERT, UPDATE, and DELETE commands).

DCL (Data Control Language)

Allows the administrator to control access to the data contained in the database.

INNER JOIN

An operation that finds matches between two tables. For each row of the first table, it looks for matches in each row of the second table.

Transaction

A set of operations that are executed atomically (all or nothing). For example, transferring funds between bank accounts is a single transaction even if it changes multiple tables.

Atomicity

Requires each transaction to be "all or nothing".

Consistency

Ensures that any transaction will take the database from one valid state to another valid state.

Isolation

Ensures that the concurrent execution of transactions results in a system state that would be obtained if these transactions were executed one after the other.

Durability

Means that once a transaction is confirmed, it will remain constant, even in the face of events such as power loss, errors, and system crashes.

Client-Server Architecture

Communication between two endpoints where one works as a client (requesting the service) and the other works as a server (offering the service).

Distributed System

A set of physically separated computers connected to each other using a network infrastructure and distributed software to work together.

Availability

The time a system or application is available, measured as the mean time between failures.

Fault Tolerance

The ability of the system to continue to operate correctly in the event of a failure of any of its components.

Scalability

The system's ability to grow with capacity needs without increasing system complexity or decreasing performance.

Transparency

Providing the user and applications with a view of a distributed system's resources as if they were managed by a single virtual machine.

Cloud Computing

A model that allows on-demand access to connectivity, computing, software, and storage services over the internet.

Private Cloud (Local Implementation)

An on-premises deployment that utilizes virtualization and application management technologies to offer dedicated resources.

Hybrid Solution

A deployment strategy that combines cloud-based resources with existing on-premises resources.

Monolithic Architecture

An architecture consisting of single, tightly integrated application components.

Dynamic Pages

Web pages where the displayed information changes continuously as it is obtained from database queries or other computational processes.